Lung cancer is one of the most commonly diagnosed malignancies and it causes more than 1 million deaths each year worldwide. Small-cell lung cancer (SCLC) accounts for about 15 to 20% of all lung cancers and it is an extremely aggressive cancer, having a response rate of 60-80% with the standard first-line chemotherapy (CT). Topotecan is a topoisomerase I inhibitor currently approved for relapsed SCLC. The authors reviewed the clinical files of SCLC's patients (pts) of a single institution, the Portuguese Institute of Oncology-Porto Centre, in a five year period. The end-points were to evaluate response rates (RR), time to progression (TTP), overall survival (OS) and toxicity profile of topotecan as a second-line treatment of SCLC. From January of 2002 to December of 2006, it was diagnosed 146 pts with SCLC, 32 were submitted to second-line treatment and 23 with topotecan. The RR was 17.4%, median TTP and median survival after topotecan were 2.8 months and 6.3 months, respectively, and median OS was 17.5 months. The incidence of grade 3 and 4 adverse events was 16.6 and 2.6%, respectively. Topotecan showed clinical activity in our unselected daily patients with relapsed SCLC, with acceptable toxicity, in accordance with the published literature.